Pembrolizumab is approved for advanced stage non-small cell lung cancer. However, the response rate is low (around 10-15 %) in patients treated in Macau SAR, China. The investigators hypothesize CD38 expressing cells and/or other immune populations will help to predict response.

Lung cancer is the leading cause of cancer death, the overall survival rate is low. Recently, using anti-PD-L1 immunotherapy for treatment of cancer shows promising in some types of cancer, including melanoma, head and neck squamous cell cancer, and lung cancer etc. Pembrolizumab is a FDA-approved anti-PD-L1 drug for treatment of advanced stage non-small cell lung cancer. In China, it is approved for used in Macau and Hong Kong. Biomarkers associated with predictive response includes PD-L1 high expression, high mutational burden, and T-cell infiltration based on several clinical trial studies in the western countries. However, the response rate is low (around 10-15 %) in patients treated in Macau SAR, China. The investigators hypothesize that immunophenotying, molecular analysis and functional characterization of CD38 expressing cells and/or other immune populations CD38 will help to identify predictive, Progression and resistance markers associated with PDL1 treatment response. The investigators will collect the blood samples of Pembrolizumab response and non-response Chinese lung cancer patients and compare the imumnophenotypic and molecular dynamic changes during treatment courses. The investigators will also examine the role of CD38 and other molecular markers associated with Pembrolizumab response, functional characterize in vitro. The molecular mechanism controlling Pembrolizumab response will be better understood for designing a better treatment strategy.

Inclusion Criteria:

• Above 18 years of age
• Locally advanced (stage IIIB) or metastatic (stage IV) NSCLC, not amenable to curative surgery or radiotherapy
• With PD-L1test available
• Progressed on previous treatment, or treatment native patients. Patients may have also received additional lines of treatment
• Received pembrolizumab treatment in the participating site.

Exclusion Criteria:

• Enrollment in studies that prohibit any participation in this observational study
• No serum samples available

The study cohort will include locally advanced or metastatic NSCLC patients with PD-L1 status available and receive pembrolizumab treatment per the judgement of treating physicians in the participating site in Macau. 30-40 patients are anticipated to be enrolled in the study, the majority of which are estimated to be from mainland China.